Gas analysis apparatus



FiledJan. 2, 1934 2' Sheets-Sheet l VENER ATTORNEY Aug. 20, 1935.

w. o. 'HEBLER (ms ANALYSISIMPPARATUS 2 Sheets-Sheet 2 Filed Jan. 2, 1934 ATTORNEY PM... M520, 1935;

UNITED A ES 2.01am GAS amnrsrs Ar mnarus PATENT OFFICE. 1

William 0. Hebler, Chatham Borough, N. 1., as-

signor to Charles Engelhard, Inc., Newark, N. J., a corporationof New Jersey 1 Application Ja nuary 2,1934, Serial No. 7o 4,91s

' 2 claims. wars-51) This invention relates to gas analysis apparatus'of the thermal conductivity type, and more particularly. to a novel arrangement and mounting of such apparatus.

I Heretofore; thermal conductivity gas analysis apparatus has comprised a number of units which -have been generally mounted in a more or less cumbersome manner, occupying an appreciable amount of space, and accordingly requiring that the installation of the apparatus be practically permanent. a

The usual gas analysis apparatusincludes a unit for scrubbing the gas to be analyzed, a stand- .ardthermal conductivity cell,a.nd a comparison cell, a galvanometer and various control devices.

- It has been customary to position the scrubbing device somewhat remotely from the conductivity cell and the gas'being analyzed was by-passed through the comparison cell, flowing directly over the resistance element carried bythe comparison cell. When the various units were mounted in a casing, such mounting was permanent and the casing could be opened only with considerable inconvenience to replace the dry cells used in connection'with the Wheatstone bridge, and in the event of the necessity of adjusting the various units, considerable labor was. necessary.

It is an object of this invention'to provide a portable gas analysis apparatus of the thermal conductivity ype inwhich the-entire apparatus is mounted upon a vertical panel, the arious units of the apparatus being arranged in a novel manner on one face of the. panel, and the controlsfor the units beingarranged on the obverse face of the panel, the panel being attachedto a casing to protect the units from dust and disarfangement by accidental blows or the like.

A further object is the provision of a novel manner of arranging thermal conductivity gas analysis apparatus upon-a vertical panel so that each unitp of the apparatus may be conveniently adjusted without interfering with or afiecting A further object is the provision of thermal.

conductivity gas analysis apparatus mounted in a novel manner upon a panel and enclosed in a casing having means therein for housing dry cells necessary for the operation of the apparatus, said panel having a readily removable plate to enable access tothe interior of the casing for the purpose of renewing the dry cells without necessitating the entire removal of the panel or in any way affecting the other units of the apparatus.

These and other advantageous objects, which will later appear, are accomplished by the simple and practical construction and arrangement of parts hereinafter described and exhibited in the accompanying drawings, forming part hereof, and

in whichr Fig. 1 is'a perspective view of the casing and panel showing the control side of the panel upon which the gas analysis apparatus is mounted,

Fig. 2 is a perspective view showing the casing open and the obverse side of the panel upon which the units of the gas analysis apparatus are arranged in a compact positi'on,-and

Fig. 3 is a sectional view of a gas analysis cell,

showingv in detail the structure thereof and the manner in which it is'mounted upon the panel. Referring to Fig. 1, the gas analysis apparatus is housed within .a casing 4 having a covering panel 5 which is provided with a window 6, through which is visible an indicating scale 1. .Mounted upon the outside face of the panel is a flow indicator 8 consistingof a transparent glass vessel which is partially filled with water.

Panel near the lower edge thereof,.is prositating removal of the panel 5. I

Mounted in a row beneath the window 6 are control lmobs ill, I], i2; and also mounted'on the panel is a pipe connection l3 through which the gas to be analyzed is introduced, andon the opposite side of the panel is mounted a guard i5 which covers apertures i6 and il-for the exhaust 'of'the gas after it has been analyzed.-

Referring to Fig. 2, in which is shown the inside face of the panel 5, it'will be noted that pipe yided with a removable plate 9 which enables access to the interior of the casing (without necesconnection I3 is connected to a tube i8 which in I turn is connected to the pipe connection I as shown in Fig. l, which "leads to the flow indicator 8.

From the flow indicator the gas is conducted by tubing [9 to a T-shaped pipe connection 20, which enables the main portion of the gas to be directly exhausted through pipe 2i d the aperture l'l,

while a portion of the gas by-passedthrough pipe 22 into a pipe T 23 which communicates with the exhaust opening IS in the panel 5.

Mounted within the vertical part of the pipe T 23 is a metal tube 24, (see Fig. 3) which has its upper end threaded and closed by means of a sealing compound 25 which may be-a wax or a hydrocarbon compound. Positioned in the tube 24 isa small porcelain tube 26 which supports a resistance element 21, which is connected to a Wheatstone bridge circuit by lead-in wires 28 passing through a seal 29 in the bottom of the pipe T 23.

- It will be seen that the pipe T 23 and the tube 24 constitute a comparison cell of a thermal conductivity gas analysis apparatus, the gas being analyzedcoming into contact with the resistance element 21 by diffusion. The gas' does not flow directly over the resistance element and consequently the analysis indications are not aflected by the rate of flow'oi gas. Adjacent the pipe T 23 is another pipe T 30 which is sealed throughout and contains a similar resistance element; the pipe T 30 with its resistance element constitutes what is called the standard or comparison ceil of the thermal conductivity gas analysis apparatus, the resistance element in the pipe T 30 being connected to the Wheatstone bridge circuit as is common and well known to persons familiar with thermal conductivity gas analysis apparatus.

Tube 24 which is threaded into pipe T 23' and a similar tube, not shown, which is connected with the pipe T 30, pass through passages in a metal block 3| and are secured thereto by nuts 32 which engage the upper threaded end of the tube 24, as shown in Fig. 3. The block '3! in turn is secured by means of a bolt 33 to a boss 34 integral with and projecting from the inside surface of the panel 5.

Also mounted on the inside surface of the panel 5 is a galvanometer generally indicated by the numeral 35, and control rheostats' 36, 31, respectively, connected to the knobs l0 and I2, and a switch 38 connected to .the knob H. The galvanometer, rheostats and thermal-conductivity cells are connected to a Wheatstone bridge circuit, which includes a plurality of resistance coils 39, mounted on the insidesuriace of panel I. Current is supplied to the Wheatstone bridge and other apparatus by means 0! dry cells 46 posi tioned in the casing 4.

From the above description and drawings, it

will be seen that the, entire gas analysis apparatus is mounted in a readily accessible manner on the inside race of the panel 5, while the controls for the'apparatus are all mounted on the outside" surface of the panel 5, thus making it unnecessary, for the purpose of operating the apparatus, to remove the panel 5 or come into contactwith various elements of the apparatus which are mounted on the inside face of the panel. Should it be necessary to add'water to the flow indicator, obviously it is not necessary to remove this panel. In making a gas analysis, it is only necessary to introduce the gas beingeanalyzed through the pipe connections l3, and then adjust the switch H and control rheostats III and i2 in a certain manner to weakror the purpose intended, they may be readl- 1y replaced with new dry cells by removing the plate 9 in the lower part of panel 5.

It will be seen that I have provided an unusual-.-

It will also'be noted that I have provided an unusually simple and economical mounting for a thermal conductivity cell as shown in detail.

in Fig. 3. The thermal conductivity cell essentially consists of the pipe T 23, a tube 24 having its upper end threaded and sealed by means of sealing compound 25, and the resistance element 21 mounted in the tube 24. This conductivity cell is very simply mounted upon a panel by passing the tube 24 through an aperture in a metal block 3| and clamping the cell in such a position by means of the nut threadedly engaging the threaded portion 01 tube 24. The block 3| may then be readily mounted on a panel by means of a bolt 33 'or any similar means. Obviously, the structure of the thermal conductivity cell and the mounting thereof as herein disclosed presents a decided improvement over the thermal conductivity cells as heretofore have been known and used. The parts of the conductivity cell may be made from standard pipe T's, standard tubing, and it is not necessary to plate the wall of the tube 24 with gold, the tube 24 forming a gas chamber, as heretofore has been the case with thermal conductivity cells, at the same time the structure enabling one or more cells to be conveniently and economically mounted in a rigid manner upon a'panel or the like.

The foregoing disclosure is to beregarded as descriptive and illustrative only and not as restrictive or llmitative of the invention, of which obviously an embodiment may be constructed including many modifications, without departing from the general scope herein indicated and denoted in the appended claims.

Having thus described my invention, what I claim as new and desire to secure byv Letters Patent, is:

1. In a gas analyzing apparatus of the thermal conductivity type-an analysis cell comprising a pipe T, a metal tube. threaded into the vertical portion of the T, said tube having its upper end threaded and closed by means of a sealing compound, a resistanceelement mounted in the tube, the gases being analyzed coming in contact with said element by diflusion only, a metal block having an aperture therein, said tube being passed through the aperture in the block, a nut threaded onto the tube and engaging the block to clamp the block between the nut and the vertical portion oi the pipe T, a panel having a-boss, and means for securing the block to the boss.

2. In a gas analysis apparatus of the thermal conductivity tim an analysis cell comprising a pipe T; a tube mounted in the vertical portion or the T-and' having its upper end threaded and closed by means 01' a sealing compound, a resistance element mounted in the tube and connected to lead-in wires passing through the horizontal portion of 'thepipe T, a metal block having an aperture throughwhich the tube said block resting upon the vertical portion of the pipe T, and a nut threaded on to the tube and engaging the ,block to clamp the block between the nut and the pipe T. WILLIAM 

